The top US wireless carriers have announced plans to fight the FCC’s fines for selling access to their customers’ location data.

The FCC announced in late April that it was fining AT&T, T-Mobile, and Verizon a combined $200 million for illegally sharing customer location data with third-party companies, as well as failing to put sufficient safeguards in place to protect that data.

“Our communications providers have access to some of the most sensitive information about us. These carriers failed to protect the information entrusted to them. Here, we are talking about some of the most sensitive data in their possession: customers’ real-time location information, revealing where they go and who they are,” FCC Chairwoman Jessica Rosenworcel said at the time. “As we resolve these cases – which were first proposed by the last Administration – the Commission remains committed to holding all carriers accountable and making sure they fulfill their obligations to their customers as stewards of this most private data.”

In statements to Mashable, all three carriers said they plan to fight the fines in court, and accused the FCC of placing blame in the wrong place.

“The FCC order lacks both legal and factual merit,” an AT&T spokesperson told the outlet. “It unfairly holds us responsible for another company’s violation of our contractual requirements to obtain consent, ignores the immediate steps we took to address that company’s failures, and perversely punishes us for supporting life-saving location services like emergency medical alerts and roadside assistance that the FCC itself previously encouraged.”

At the heart of the issue is how data aggregators the carriers had deals with used the data they had access to, with all three companies blaming these other companies for the misuse of customer data. Further complicating the issue is that both Verizon and T-Mobile shut down the aggregator location services several years ago.

“In this case, when one bad actor gained unauthorized access to information relating to a very small number of customers, we quickly and proactively cut off the fraudster, shut down the program, and worked to ensure this couldn’t happen again,” a Verizon spokesperson told Mashable.